Flexible screw and transport apparatus comprising same

Abstract

The flexible screw of the invention comprises a flexible rod and a cord helically set on the rod, and can be installed along straight and curved paths of transport. It ensures smooth transport of containers and provides container transport apparatus of simplified construction at reduced cost. Moreover, abrasion of pipe during transport of powder and granular material can be reduced. The container transport apparatus of the present invention is equipped with the screw mentioned above and a guide, or two screws, the members of each pair being positioned in parallel at a given distance, and transfers containers held by the screw and the guide, or the two screws by rotating the screw(s). The container transport apparatus of the present invention enables smooth transport of containers even through a curved path, reduces maintenance cost of the screw(s) during operation, and inhibits abrasion of the rail to a considerable degree. Further, the powder and granular material transport apparatus of the present invention reduces abrasion of pipe.

What is claimed is: 
     
       1. A flexible screw comprising: a flexible rod comprised of a metal rope and a resin layer coated on said metal rope; and   a cord-shaped element helically mounted on said flexible rod and being of resin and having a core of a bundle of fibers for making said cord-shaped element substantially inextensible.   
     
     
       2. A screw according to claim 1, wherein the resin material of the resin layer applied on the metal rope has a wear rate of not more than 5×10 -4  mm 3  /kg·m. 
     
     
       3. A screw according to claim 1, wherein the resin material of the resin layer applied on the metal rope has a coefficient of dynamic friction of not more than 1.0. 
     
     
       4. A screw according to claim 1, wherein the resin material of the cord has a specific wear rate of not more than 5×10 -4  mm 3  /kg·m. 
     
     
       5. A screw according to claim 1, wherein the resin material of the cord has a coefficient of dynamic friction of not more than 0.4. 
     
     
       6. A transport apparatus comprising a rotatable screw having a flexible rod and a cord-shaped element helically set on said rod, and a guide, said screw and said guide extending in parallel along the entire length of said screw and at a specified distance from each other to define a transport path therebetween having a width for holding a container to be transported between and in contact with the screw and the guide for transporting said container along the transport path by rotating the screw. 
     
     
       7. A transport apparatus according to claim 6, comprising a sensor for detecting reject containers and a reject containers-removing system which removes reject containers from the transport path in response to the sensor. 
     
     
       8. A transport apparatus according to claim 6, wherein at an input end, the transport path is increased in width and equipped with a feeder means for transferring containers to a position where the containers are to be held by the path. 
     
     
       9. A transport apparatus according to claim 6, comprising a delivery direction changing means for changing the delivery direction of containers while retaining a given width of a transport path at the delivery end. 
     
     
       10. A transport apparatus according to claim 6, wherein the specified distance is a space width enough for holding the neck of containers. 
     
     
       11. A transport apparatus comprising: a screw having a flexible rod and a cord helically set on said rod;   a guide, said screw and said guide extending in parallel at a specified distance from each other to define a transport path therebetween, whereby containers held between the screw and the guide are transported along the transport path by rotating the screw; and   a rail having means for attracting the screw toward said rail.   
     
     
       12. A transport apparatus according to claim 11, comprising an attracting means set in the rail for attracting the screw to prevent derailment. 
     
     
       13. A transport apparatus according to claim 11, wherein the rail is made of a metal. 
     
     
       14. A transport apparatus according to claim 11, wherein a circular-arc groove is formed in the shelf on a rail for attracting the screw to accommodate part of the screw. 
     
     
       15. A transport apparatus as claimed in claim 11 further comprising a sensor for detecting reject containers and a reject containers-removing system which removed reject containers from the transport path in response to the sensor. 
     
     
       16. A transport apparatus as claimed in claim 11 wherein on the feeding end the transport path has an increased width and has a feeder means for transferring containers to a position where the containers are held in said transport the path. 
     
     
       17. A transport apparatus as claimed in claim 11 further comprising a delivery direction changing means for changing the delivery direction of containers while retaining a predetermined width of said transport path at the delivery end.